Eccentric driving gear



Aug. 29, 1944. A. R. J. WILKINSON ECCENTRIC DRIVING GEAR 2 Sfieets-Sheet 1 Filed June '5, 1945 mm? vm v I n ventor;

A. R. J. 'WILKLNSON- 2,357,247

EGGENTRIC' DRIVING GEAR Filed Jun s} 1945 Inv Attorney & mm NNMNNB ov @w.mw fl 3 Wm w mmw \wmw 899 mm 3 W6C x. Q

Patented Aug. 29, 1944 ECGENTRIC' DRIVING GEAR Albert Richard James Wilkinson, Twickenham,

England, assignor of on 5011, Richmond, Surrey, England Application June 3, 1943, Serial No. 489,537

In Great Britain October 30, 1942 1 11; Claims.

This invention relates to. driving mechanism and has f i O ct to. ro ide mech ism whereby a shaft can be driven at a high speed by'a prime movensuch. anjinternal combustion or other engine.

Generally an eccentric has driven its housing, in the form of a. sheave.

In the present invention thehousing Of an eccentric servesto drive the eccentric. arrangement enables more satisfactorybalancing to be obtained than is the case with a crank.

According to the present invention, an eccentric, keyed to a shaft, is mounted in a house ing capable of slidingin' a, frame which is adapted to be driven in a direction at right angles to the direction of movement of the housing by a prime mover located on one side of the frame or by two oppositely located prime movers which are timed to drive the frameisuccessively in opposite directions.

On the shaft may'also be keyed a fly wheel, the eccentric preferably projecting from'one face of the fly wheel whilst the other face ofthe fly wheel, directly opposite the eccentric, has a recess of exactly the same volume and shape as the eccentric, the weight of metal removed corresponding with the weight of the eccentric.

The eccentric and fly wheel are preferably formed as an integral unit,

Preferably two eccentrics and associatedfly wheels are keyed to the same shaft, the eccentrics being relatively displaced by 180 and operating with separate housings each with its own frame and pairof prime movers, except for steam engines where the eccentrics are relatively displaced by about 30.

If desired two prime movers may act on one or both sides'of a frame. j

The prime movers are preferably internal combustion engines.

With an eccentric preferably engage two pairs of shoes one shoe of each pair being a pressure shoe, whilst the other shoe, for convenience will be called a centre shoe, the centre shoe of each pair being located diametrically opposite one another at opposite ends'of a horizontal line drawn" through the centre of the shaft and the centre of the eccentric when the eccentric is in its fully extended right hand position. a

The right hand centre shoe extends about two thirds of its length above the horizontal line whilst the other centre shoe extends for an equal distance in the opposite direction.

The pressure shoe on the right hand side is below its corresponding centre shoe, whilst the left hand pressure shoe is above its corresponding centre shoe. h

The shoes are each of a length which is equal to aboutone sixth of lthecircumferenceof the I, and

e-half to Eric Richardeccentric, the spaces in the housing between the shoes serving as oil reservoirs.

The shoes of each pair are pivotally mounted at the ends of a rocker bar mounted in the housing; The pivotal point of the rocker bar may be varied so a to vary the leverage.

The pressure shoes during the driving stroke of their prim mover or. prime movers are acted upon by hydraulic pressure fromchambers formed between the housing and the frame.

The invention will now be described by way of example W th, reference to the accompanying drawings, wherein:

Fig. 1 is a side elevation of a driving mechanism actuated by eight prime movers,

Fig. 2 is a section on the line IIII of Fig.

Fig. .3 i a section on the line III-III of Fig. 1.

As shown in Figs. 1 and 2 a shaft I has keyed thereto two fly Wheels 3, 4 and two eccentrics 5, 6. The eccentrics 5, 6 may be formed integral with the fly wheels 3, 4.

', For balancing purposes a recess 1, 8 is formed in each flywheel 3,T4, this recess being on the opposite face to the eccentric 5, 6 and being of the same shape and volume as the eccentric 5, 6.- In other words there is removed from the flywheel 3, 4 a mass of metal corresponding in shape and weight with the eccentric 5, 6 and located directly opposite thereto.

The two flywheels 3, 4 may be bolted, riveted, welded or otherwise secured together, with the eccentrics 5, 6 projecting from opposite, sides thereof and relatively displaced by 180.

Each eccentric 5, 6 is mounted in a separate housing 9, It! provided at each end with a tongue ll. The tongue H engage with correspondinggrooves in a frame formed of vertical members I 2 braced together by tie rods l3.

To each verticalmember i2 are secured the piston rods M of pistons Hi. The piston rods M are preferably secured to their pistons l5 in such a manner as to permit of relative universal rocking movement under spring tension.

Each piston I5 i preferably provided with an integral sleeve 63 (Fig. 2) into which is slidably fitted. under the action of a spring washer 64, a cup member 65. With the cup member 65 en gagesaball 66. secured to the end of the piston rod M. The ball 66 is held against the cup member 65 by-a member 6'! which is screwed into the sleeve 63 and is prevented from disengagement therefrom by any suitable means, such as for examplea split pin 68.

The pistons form part of any suitable prime mover such as for example an internal combustion engine.

With each eccentric 5, 6 co-operate four shoes 16, 11, l8, l9. 1

As shown in the drawings each shoe, I 6, ll,

centric 5, 6, so as to leave a space of a length of about one sixth of the circumference of the eccentric between each pair of shoes I6, I'I, I8, I9.

The shoes I'I, I9, which will be referred to as centre shoes, have substantially two thirds of their length located respectively above and below The arrangement in connection with eccentric 6 is the same as hereinbefore described with reference to the eccentric except that the drawing would have to be turned over as the eccentric 6' is displaced by 180 relatively to the eccentric 5. The prime movers are timed so as to operate in the proper sequence, that is to say the right hand a line passing through the centre 2| of the shaft I and the centre 22 of the eccentric 5.

The shoes I6, I8, hereinafter referred to as pressure shoes, are arranged respectively below and above the centre shoes I1 and I9.

The shoes I6, I1 and I8, I9 are each provided with a pair of upstanding lugs which straddle the housing 9 and by which they are pivoted at 23, 24, 25, 26 to pairs of rocker arms 21, 28 located outside the lugs and'pivotally mounted in the housingS at 29, 30. The pivots 29, 30 are preferably adjustable to vary leakage.

In order to enable the shoes I6, I'I, I8, I9 to be fitted in position between the eccentric 5 and the housing 9, the latter is provided with openings 3| which allow the lugs of the shoes to pass through th housing 9 and engage with the opposite sides thereof.

The pivots 23, 24, 25, 26 pass through suitable clearance holes in the housing 9.

The pressure shoes I6, 18 are forced into engagement with the eccentric by pistons 3I, 32 provided with openings for the passage of the pivots 23, 25. The pistons are subjected to oil pressure from chambers 33, 34. The chambers 33, 34 are formed by forming a recess 35, 36 in th vertical sides of the housing 9 and recesses 31, 38 in the vertical members I2. The recesses 31, 38, which are of larger cross sectional area than the recesses 35, 36, are each provided with a vent 39, and are closed at theirouter ends by outwardly projecting portions 9' on the housing 9.

Oil is supplied to the chambers 33 and 34 through a bore 46, in the shaft I, which 'communicates by passages 4 I, 42 with the recesses 43,

44 in shoes 59, and passages 45, 46 provided with non-return ball valves 41.

The shoes 59 substantially fill the spaces between the shoes IT and I8, and I6 and I9, and are each provided with a threaded hole 5I into which is screwed a nipple 52 after the shoes 50 have been placed between the eccentric 5 and the housing 9. Th nipples 52 are provided at the outer ends with diametrically oppositely located slots 53 for engagement by a screw-driver. The nipples 52 are engaged with the shoes 50 through threaded holes 54 in the housing 9. The nipples 52 are of smaller diameter than the holes 54 so that they pass freely therethrough and are pref erably provided with a smooth outer surface at th portion thereof which is normally located in the holes 54.

The shoes 59 are pressed againstthe eccentric 5 by springs 55 which are pressed against the nipples 52 by screw plugs 56 which are screwed into holes 54.

The shoes 56 are preferably provided with a' flange 51 which slightly overlaps the outer face of th eccentric 5 when the shoes are in the op-- erative position.

The ball valves 41 are prevented from leaving their housings 58 by plates 59 secured to the housing 9 by screws 60.

The recesses 31, 38 are each provided with an outlet 6| controlled by an adjustable safety valve 62.

pistons I5 associated with the frame I2 of the eccentric 5 and the left hand pistons I5 associated with the frame I2 of the eccentric 6 are carryingout their power stroke and th remain- 2 ing pistons I5 are carrying out their return stroke and vice versa.

The operation of the mechanism will now be described from the position shown in Fig. l, and assuming that th pistons connected to the right hand side of the frame of the eccentric 5 are carrying out their power stroke, thus moving inwardly, and the remaining pistons are carrying out their return stroke, that is to say moving outwardly. The pressure applied by the piston 3! against the pressure shoe I6, applies this latter firmly against the eccentric 5 whilst at the same time slightly lifting the centre shoe I'I from the eccentric 5.

As a result the eccentric 5 is lifted and the housing 9 travels upwardly and at the same time moves towards the, left. During this movement the parts 35, 31 of the chamber 33 pass over one another whereby the pressure of the oil on the piston 3I is increased. At the same time the end wall 48 of thehousing 9 exposes the vent 39 so as to relieve the pressure on the shoe I8.

Whilst the pressure acts on the pressure shoes I6, I8 the centre shoes are disengaged from the eccentric 5. a

The pressure shoe I6 continues to apply pressure to the eccentric 5 until th housing 9 reaches its uppermost position, when the eccentric 5 is also in its uppermost position.

The housing 9 now commences its downward movement, whilst still continuing its movement to the left, towards its mid position. During this movement of the housing the pressure on the pressure shoe I6 decreases so that the centre shoes II, I9 takeover to mov the eccentric 5 over the dead centre position.

During this operation the eccentric 5 has moved in an anti-clockwise direction and the pistons on the right hand side have completed their power stroke.

The pistons on the left hand side now come into operation and the eccentric 5 is caused to continue its rotation in an anti-clockwise direction until it returns to the position shown. During this movement of the eccentric 5 the housing 9 has been moved through its extreme lowermost position and back to its starting position as a result of the lateral movement which is imparted thereto as a result of the action of the eccentric 5 and the left hand pistons. During this movement the right hand pistons carry out their return stroke whilst the piston 32 forces the shoe I8 against the eccentric 5 first with increasing pressure and then with decreasing pressure as above described in connection with the piston 3|.

The eccentric 5 has thus carried out a complete revolution. The operations above described are carried out for each succeeding revolution.

The drive through the eccentric 6 is the same as that above described except that the corresponding housing I0 is first moved downwardly from a mid positionto its extreme lower position then upwardly through a mid position to its extreme upper position, whilst being moved at the same time towards the right.

Four prime movers on each side are preferred,

case the piston rods act centrally on the frames.

It will also be understood that the mechanism may include only a single eccentric with its fly wheel, housing and frame, with a single prime mover or a pair of prime movers acting on each side of the frame.

The prime movers may be internal combustion engines, double acting steam engines, compressed air engines, pumps, or any type of engine having a reciprocating member for driving the frame.

In the case of steam engines the eccentrics 5, 6 are preferably displaced by about 30 to avoid dead centre positions as occur in the case of locomotives.

By means of the present invention a considerable increase in leverage is obtained as an eccentric has a much greater throw than a crank whilst it can be balanced more easily.

By arranging the centre shoes ll, l9 so as to extend above and below the centre line 2i! there is obtained the advantage that they apply pressure to the eccentric whilst it is still in throw when passing over the dead centre position.

1. In a driving mechanism, the combination comprising a frame adapted to be reciprocated, a housing mounted in said frame, said housing sliding in said frame in a direction at right angles to the movement of said frame, said housing having a circular opening therein, an eccentric engaging said opening, a flywheel on which said eccentric is mounted eccentrically on one face of said eccentric, said eccentric being provided on its opposite face with a recess, said recess being directly opposite said eccentric and being of exactly the same volume and shape as said eccentric, the weight of metal removed from the flywheel for forming said recess corresponding with the weight of said eccentric, and a driven shaft passing axially through said fly wheel and having said flywheel keyed thereto.

2. In a driving mechanism the combination comprising a driven shaft, a pair of flywheels keyed on said shaft, two eccentrics formed integral one with each flywheel, said eccentrics projecting from the remote faces of said flywheels and being relatively angularly displaced, the adjacent faces of each of said eccentrics having a recess therein, each recess being directly opposite the eccentric of the corresponding flywheel, each recess being of exactly the same volume and shape as the corresponding eccentric, the weight of metal removed from the flying wheel for forming the recess corresponding with the weight of the eccentric, a pair of housings each having an opening therein, said openings being engaged by said eccentrics, and a pair of guides engaged one by each of said housings.

3. A mechanism according to claim 1 including a pair of prime movers, said prime movers acting one on each side of said frame.

4. A mechanism according to claim 2, including four prime movers, two of said prime movers being located on opposite sides of said frame, two

of said prime movers being adapted to move said frames in one direction whilst the other two prime movers are adapted to move the two frames in the opposite direction. 4

5. A mechanism according to claim 2, wherein said eccentrics are relatively displaced by 6. A mechanism according to claim 2 wherein said eccentrics are relatively displaced by about 30.

7. A mechanism according to claim 1, including two pairs of shoes between said eccentric and said housing, said pairs of shoes being separated from one another at eachend by a distance substantially equal to the length of one of the shoes, the division points between the shoes of each pair being diametrically opposite one another.

8. A mechanism accordin to claim 1, including two pairs of shoes between said eccentric and said housing, said pairs of shoes being separated from one another at each end by a distance substantially equal to the length of one of the shoes, the division points between the shoes of each pair being diametrically opposite one another, each of said shoes extending over about one sixth of the circumference of said eccentric, the pairs of shoes being spaced apart a distance substantially equal to the length of one of the shoes.

9. A mechanism according to claim 1, including two pairs of shoes between said eccentric and said housing, said pairs of shoes being separated from one another at each end by a distance subthe division points between the shoes of each pair being diametrically opposite one another, and a pair of rocker bars each pivotally mounted intermediate its ends on said housing, one of the rocker bars being associated with each pair of shoes, one of the shoes being pivotally mounted at the end of each bar.

10. A mechanism according to claim 1, including two pairs of shoes between-said eccentric and said housing, said pairs of shoes being separated from one another at each end'by a distance substantially equal to the length of one of the shoes, the division points between the shoes of each pair being diametrically opposite one another, and a pair of rocker bars each pivotally mounted intermediate its ends on said housing, one of the rocker bars being associated with each pair of shoes, one of the shoe being pivotally mounted at the end of each bar, pressure chambers formed between the adjacent sides of said housing and said frame, a pressure medium in each of said chambers, said housing having passages therein extending from said chambers to the opening in said housing adjacent one of the shoes of each pair, and two pistons located one in each of said passages, one of the shoes of each pair being connected to said pistons.

11. A mechanism according to claim 1, including two pairs of shoes between said eccentric and said housing, said pairs of shoes being separated from one another at each end by a distance substantially equal to the length of one of the shoes, the division points between the shoes of each pair being diametrically opposite one another, hydraulic pressure means associated with one shoe of each pair, means for reducing the hydraulic pressure on one shoe when the hydraulic pressure on the other shoe is increased.

ALBERT RICHARD JAMES WILKINSON. 

